Blade Element Mounting In A Snow Plough

ABSTRACT

Flexible suspension of colter element ( 1 ) of a snowplough furnished with a body ( 5 ), a blade ( 3 ) as its extension, colter element ( 1 ) that gets in contact with the surface to be ploughed, where for the colter element ( 1 ) a tilt suited for the purpose is arranged, a.o. a cutting angle. Colter element ( 1 ) is fitted to dodge an obstacle in its cutting angle by backing up, whereby the fixing arrangement of colter element ( 1 ) has an open space formed for moving plate ( 13 ) fitted as extension of the colter element, in which space said moving plate is arranged to glide, and the arrangement includes a spring organ ( 9 ) the spring impact of which is arranged to hinder the colter element from backing up.

The invention relates to a flexible mounting of the colter element of a snowplough furnished with a colter element that gets in contact with the surface to be ploughed including a blade as its extension, by which suspension for the colter element a tilt, a.o. a cutting angle, suited for the purpose is arranged. When the snowplough is ploughing uneven ground the colter must adjust to the roughness of ground. The flexible colter material is not enough alone, but the suspension of the colter must also be flexible. The need of flexibility grows with the width of the snowplough and the demands of the plough cleanliness.

In using flexible colters of polyurethane or rubber the load of colter against the surface to be ploughed must be small, but the colter must stay in same colter angle during flexing. The smallness of vertical force pressing colter is important in order to minimize wear and tear of the colter and to lengthen the life of the colter. Right position keeps the cutting of colter edge sharp without rounding the lower surface. Rounding of colter lower surface makes of the cutting colter edge rise from the ground and snow getting under the colter lifts the colter to glide on the snow layer. The result is weakened ploughing quality.

Backing of colter in its direction against a spring is known for instance from publications DE 881200, GB 1060335, GB 784049. In these ones the colter element is a plate of large size, which must always be replaced as a whole, when sufficiently worn out. For the colter plate a quite long backward directed steering box portion is arranged, which keeps the colter in direction.

In using an additional colter, this colter must have same possibilities to follow the roughness of surface as the first colter.

Previously known is suspension of a colter, where the whole plough, for the part of blade and colter, is divided into transverse elements, which are flexing vertically on levers or on flexible attachments. The disadvantage of this solution are the relatively heavy elements, which cause the colters a wearing load and hard strokes on obstacles by ploughing, because of the mass of elements. The moving of elements gives cause to discontinuity on blade surface and restricts blade forming. The circle curve is almost the only possible cross-cut of blade, if the motion is dimensioned to follow the curve. The direction of the evasive movement by means of lever mechanisms is in a relatively great angle in regard to the driving motion direction and thus disadvantageous.

Previously known is also a solution, where the mere colter is divided into separately suspended elements, which function simply steered by springs or separate elements, as GB 784049. There are wearing parts in the control mechanisms. Colters resting merely on springs have too great colter forces and often insufficient control, which lead to rapid wearing and blade bottom rounding. Known is also a solution, where the colter is suspended on springs of elastic rubber or of plastic.

The disadvantage of said solutions is weak control, whereby the colter wears out into wrong form. Another disadvantage appears bin speedy ploughing and the risk connected to overheating of spring material, and loss of spring material firmness due to inside frictions.

For suspension of an additional colter a further solution is known, where the additional colter is furnished with its own mechanisms both for the vertical and evasive backward motion of the colter. This is an expensive solution containing of many parts.

By means of the solution according to this invention most of the disturbances appearing by the colter suspension are avoided and the suspension according to this invention is characterized in that to the spring organ a detachable colter element is attached, as extension to witch a plate attached to the colter element is fitted, for which plate an open space is formed between the attached colter and a covering plate at a distance from it, whereby said moving plate is fitted to glide in the said open space.

The advantage of the suspension according to this invention is each colter element and that to it possibly connected additional colter is built as a flexible unit, which due to its flexible attachment gets with its both colters in contact against the surface. The additional colter can be fixed to the attachments of the colter, whereby the additional colter follows the colter motions. This approximate control is sufficient when both colters are flexible. The additional colter has a stabilizing extra impact on the actual colter. At the same time, the sequential colters give in the manner of the boggie each other the control to keep the colters in right working direction.

In the following the invention is disclosed with reference to the enclosed drawing, where

FIG. 1 shows a snow plough viewed from the end.

FIG. 2 shows the sectional view II-II of the construction in FIG. 1.

FIG. 1 shows a snowplough colter 3 furnished with body 5, height adjusting support wheel 6 and colter 1 including blade 3 as its extension. Colter 1 is of flexible material and supported by means of holders 8. There is in the body lower part a horizontal beam 2 in which the colter elements 1 and lower edge 4 of blade 3 are fixed.

As extension of colter 1 there is a moving plate 13, which can move between the surface of fixed blade 3 and cover plate 12. Colter 1 is attached to moving plate 13 and to the flexing lower end of spring organ 9. The upper end of spring organ 11 is attached to horizontal beam 2 by means of a distance piece 18. As spring there is a leaf spring bent into U-shape. Cover plate 12 is attached immovable in regard to fixed blade 3. Moving plate 13, cover plate 12, and fixed blade 3 are all at least partly overlapping each other.

The spring U-shape tends to open and by colter backing the U-shape tends to narrow, in other words fixing points 10 and 11 (FIG. 2) come closer to each other.

FIG. 1 shows also an additional colter 15, which is by means of shaft 16, bent of spring steel, attached to colter 1. Thus the additional colter 15 flexes like colter 1 in the flexing direction of colter 1.

FIG. 2 shows a portion of the plough lower part from behind. U-shaped leaf springs 9 tend to open and press colter 1 down. Stoppers 14 are connected to the end, which prevent colter 1 to get down only to a certain limit, even if spring 9 would tend to press the colter more downward. By means of this stopper solution for the colter initial stress is achieved to prevent backing. Thanks to the solution the springback factor of the spring remains almost unchangeable on a possible backing distance arranged for the colter. Between spring 9 lower fastening and colter 1 there can also be a damping piece 17.

The colter element is attached at least between the ends of two leaf springs 9 bent into U-shape and running in colter direction, while the other spring ends are attached to the plough body. U-shaped leaf springs function as rough straight-through mechanisms. The holding power in the direction of motion caused by bumpy surface is smallest and at its greatest in the direction that keeps the colter in right position. The arrangement presses the colter with a relatively small load against the surface being ploughed and at the same time keeps the colter steady in cutting position.

The advantage of prestressed spring suspension is the possibility of relatively small growth of the springback factor, while the spring route gets longer and at the same time for the colter an operating area is achieved at once after the limitation without any additional routes of motion, which would demand additional height for plough lifting, for instance in transporting position.

Advantageously the plough is formed of several colter elements side by side, which have separated flexing arrangements. Then only relatively small masses have to back up on hitting an obstacle. Even the ploughing result weakens only at the backed up colter. Blade portion 3 can be continuous along the whole plough width. 

1. Flexible suspension of colter element (1) of a snowplough furnished with a body (5), colter element (1) that gets in contact with the surface to be ploughed, blade (3) as its extension, where for the colter element (1) a tilt suited for the purpose is arranged, a.o. a cutting angle, and that colter element (1) is fitted to dodge an obstacle in its cutting angle by backing up against spring organ (9), characterized in that colter element (1) is detachably attached to spring organ (9) to which extension a plate (13), attached to colter element, is fitted, for which an open space is formed between fixed blade (3) and cover plate (12) which is at a distance from its front, whereby said moving plate (13) is fitted to glide in said open space.
 2. Flexible suspension according to claim 1, characterized in that the spring organ solution includes at least two in U-shape bent leaf springs (9) in the colter direction, one ends of which are attached to the body and the other ends to colter element (1),while the leaf springs work as essential straight-through mechanisms.
 3. Flexible suspension according to claim 1, characterized in that cover plate (12) is immobile in regard to fixed blade (3) and at least partly overlapping with blade (3).
 4. Flexible suspension according to claim 1, characterized in that moving plate (13) is at least partly overlapping with blade (3).
 5. Flexible suspension for colter (1) and for the additional colter following it at the back according to claim 1, characterized in that for said colters a common flexible suspension is arranged by means of fixing devices (19-13) 